Smart speaker ownership in the US jumped from 36 million units at the end of the fourth quarter of 2017 to 66 million units at the end of last December, says a Tuesday report from market data firm Consumer Intelligence Research Partners.

“Holiday shoppers helped the smart speaker market take off again,” CIRP partner Josh Lowitz said in a statement. “Amazon and Googleboth have broad model lineups, ranging from basic to high-end, with even more variants from Amazon. Apple of course has only its premium-priced HomePod, and likely won’t gain significant share until it offers an entry-level product closer to Echo Dot and Home Mini.”

The research also found that the number of people with more than one smart speaker increased from 18 percent to 35 percent over the last year.

“Amazon and Google have succeeded in selling multiple units to a single household,” CIRP partner Mike Levin said in a statement. “Their strategies appear to include persuading owners to use smart speakers in multiple rooms, which helps create more active usage of the voice platform.”